OpenSceneGraph/src/osgUtil/TriStrip_tri_stripper.h
2007-04-06 15:36:13 +00:00

385 lines
9.8 KiB
C++

// tri_stripper.h: interface for the tri_stripper class.
//
//////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002 Tanguy Fautré.
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.eap_array.h TriStrip_tri_stripper.cpp TriStrip_tri_stripper.h
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
// Tanguy Fautré
// softdev@pandora.be
//
//////////////////////////////////////////////////////////////////////
//
// Tri Stripper
// ************
//
// Current version: 1.00 BETA 5 (10/12/2002)
//
// Comment: Triangle stripper in O(n.log(n)).
//
// Currently there are no protection against crazy values
// given via SetMinStripSize() and SetCacheSize().
// So be careful. (Min. strip size should be equal or greater
// than 2, cache size should be about 10 for GeForce 256/2
// and about 16-18 for GeForce 3/4.)
//
// History: - 1.00 BETA 5 (10/12/2002) - Fixed a bug in Stripify() that could sometimes
// cause it to go into an infinite loop.
// (thanks to Remy for the bug report)
// - 1.00 BETA 4 (18/11/2002) - Removed the dependency on OpenGL:
// modified gl_primitives to primitives,
// and gl_primitives_vector to primitives_vector;
// and added primitive_type.
// (thanks to Patrik for noticing this useless dependency)
// - 1.00 BETA 3 (18/11/2002) - Fixed a bug in LinkNeightboursTri() that could cause a crash
// (thanks to Nicolas for finding it)
// - 1.00 BETA 2 (16/11/2002) - Improved portability
// - 1.00 BETA 1 (27/10/2002) - First public release
//
//////////////////////////////////////////////////////////////////////
#ifndef TRISTRIP_TRI_STRIPPER_H
#define TRISTRIP_TRI_STRIPPER_H
// include this to supress daft VisualStudio warnings.
#include <osg/Export>
#include <algorithm>
#include <deque>
#include <list>
#include <map>
#include <string>
#include <vector>
// namespace triangle_stripper
namespace triangle_stripper {
#include "TriStrip_graph_array.h"
#include "TriStrip_heap_array.h"
typedef unsigned int indice;
class triangle
{
public:
triangle();
triangle(const indice A, const indice B, const indice C);
void SetStripID(const size_t StripID);
indice A() const;
indice B() const;
indice C() const;
size_t StripID() const;
private:
indice m_A;
indice m_B;
indice m_C;
size_t m_StripID;
};
class triangle_edge
{
public:
triangle_edge(const indice A, const indice B, const size_t TriPos);
indice A() const;
indice B() const;
size_t TriPos() const;
private:
indice m_A;
indice m_B;
size_t m_TriPos;
};
class triangle_degree
{
public:
triangle_degree();
triangle_degree(const size_t TriPos, const size_t Degree);
size_t Degree() const;
size_t TriPos() const;
void SetDegree(const size_t Degree);
private:
size_t m_TriPos;
size_t m_Degree;
};
class triangle_strip
{
public:
enum start_order { ABC = 0, BCA = 1, CAB = 2 };
triangle_strip();
triangle_strip(size_t StartTriPos, start_order StartOrder, size_t Size);
size_t StartTriPos() const;
start_order StartOrder() const;
size_t Size() const;
private:
size_t m_StartTriPos;
start_order m_StartOrder;
size_t m_Size;
};
struct _cmp_tri_interface_lt
{
bool operator() (const triangle_edge & a, const triangle_edge & b) const;
};
struct _cmp_tri_degree_gt
{
bool operator () (const triangle_degree & a, const triangle_degree & b) const;
};
class tri_stripper
{
public:
// New Public types
typedef std::vector<indice> indices;
enum primitive_type {
PT_Triangles = 0x0004, // = GL_TRIANGLES
PT_Triangle_Strip = 0x0005 // = GL_TRIANGLE_STRIP
};
struct primitives
{
indices m_Indices;
primitive_type m_Type;
};
typedef std::vector<primitives> primitives_vector;
struct triangles_indices_error { };
// constructor/initializer
inline tri_stripper(const indices & TriIndices);
// Settings functions
inline void SetCacheSize(const size_t CacheSize = 16); // = 0 will disable the cache optimizer
inline void SetMinStripSize(const size_t MinStripSize = 2);
// Stripper
void Strip(primitives_vector * out_pPrimitivesVector); // throw triangles_indices_error();
private:
friend struct _cmp_tri_interface_lt;
typedef common_structures::graph_array<triangle, char> triangles_graph;
typedef common_structures::heap_array<triangle_degree, _cmp_tri_degree_gt> triangles_heap;
typedef std::vector<triangle_edge> triangle_edges;
typedef std::vector<size_t> triangle_indices;
typedef std::deque<indice> indices_cache;
void InitCache();
void InitTriGraph();
void InitTriHeap();
void Stripify();
void AddLeftTriangles();
void LinkNeighboursTri(const triangle_edges & TriInterface, const triangle_edge Edge);
void MarkTriAsTaken(const size_t i);
triangle_edge GetLatestEdge(const triangle & Triangle, const triangle_strip::start_order Order) const;
triangle_strip FindBestStrip();
triangle_strip ExtendTriToStrip(const size_t StartTriPos, const triangle_strip::start_order StartOrder);
void BuildStrip(const triangle_strip TriStrip);
void AddIndice(const indice i);
void AddIndiceToCache(const indice i, bool CacheHitCount = false);
void AddTriToCache(const triangle & Tri, const triangle_strip::start_order Order);
void AddTriToIndices(const triangle & Tri, const triangle_strip::start_order Order);
const indices & m_TriIndices;
size_t m_MinStripSize;
size_t m_CacheSize;
primitives_vector m_PrimitivesVector;
triangles_graph m_Triangles;
triangles_heap m_TriHeap;
triangle_indices m_NextCandidates;
indices_cache m_IndicesCache;
size_t m_StripID;
size_t m_CacheHits;
};
//////////////////////////////////////////////////////////////////////////
// tri_stripper Inline functions
//////////////////////////////////////////////////////////////////////////
inline tri_stripper::tri_stripper(const indices & TriIndices) : m_TriIndices(TriIndices) {
SetCacheSize();
SetMinStripSize();
}
inline void tri_stripper::SetCacheSize(const size_t CacheSize) {
m_CacheSize = CacheSize;
}
inline void tri_stripper::SetMinStripSize(const size_t MinStripSize) {
m_MinStripSize = MinStripSize;
}
inline triangle::triangle() { }
inline triangle::triangle(const indice A, const indice B, const indice C) : m_A(A), m_B(B), m_C(C), m_StripID(0) { }
inline void triangle::SetStripID(const size_t StripID) {
m_StripID = StripID;
}
inline indice triangle::A() const {
return m_A;
}
inline indice triangle::B() const {
return m_B;
}
inline indice triangle::C() const {
return m_C;
}
inline size_t triangle::StripID() const {
return m_StripID;
}
inline triangle_edge::triangle_edge(const indice A, const indice B, const size_t TriPos) : m_A(A), m_B(B), m_TriPos(TriPos) { }
inline indice triangle_edge::A() const {
return m_A;
}
inline indice triangle_edge::B() const {
return m_B;
}
inline size_t triangle_edge::TriPos() const {
return m_TriPos;
}
inline triangle_degree::triangle_degree() { }
inline triangle_degree::triangle_degree(const size_t TriPos, const size_t Degree) : m_TriPos(TriPos), m_Degree(Degree) { }
inline size_t triangle_degree::Degree() const {
return m_Degree;
}
inline size_t triangle_degree::TriPos() const {
return m_TriPos;
}
inline void triangle_degree::SetDegree(const size_t Degree) {
m_Degree = Degree;
}
inline triangle_strip::triangle_strip() : m_StartTriPos(0), m_StartOrder(ABC), m_Size(0) { }
inline triangle_strip::triangle_strip(const size_t StartTriPos, const start_order StartOrder, const size_t Size)
: m_StartTriPos(StartTriPos), m_StartOrder(StartOrder), m_Size(Size) { }
inline size_t triangle_strip::StartTriPos() const {
return m_StartTriPos;
}
inline triangle_strip::start_order triangle_strip::StartOrder() const {
return m_StartOrder;
}
inline size_t triangle_strip::Size() const {
return m_Size;
}
inline bool _cmp_tri_interface_lt::operator() (const triangle_edge & a, const triangle_edge & b) const {
const indice A1 = a.A();
const indice B1 = a.B();
const indice A2 = b.A();
const indice B2 = b.B();
if ((A1 < A2) || ((A1 == A2) && (B1 < B2)))
return true;
else
return false;
}
inline bool _cmp_tri_degree_gt::operator () (const triangle_degree & a, const triangle_degree & b) const {
// the triangle with a smaller degree has more priority
return a.Degree() > b.Degree();
}
} // namespace triangle_stripper
#endif